Tray structure for liquid treating apparatus



United States Patent O TRAY STRUCTURE FOR LIQUID TREATIN G APPARATUS Robert W. Wolf, Philadelphia, Pa., assignor to Heintz Manufacturing Company, Philadelphia, Pa., a corporation of Pennsylvania Application August 18, 1950, Serial No. 180,282

6 Claims. (Cl. 211--41) This invention relates to article supporting structure of an improved nature for use in the vat of liquid treating apparatus, and more particularly the invention relates to dish supporting trays for use in an automatic dishwashing machine.

In the designing of automatically operable equipment for treating articles with liquid, such as automatic dishwashing machines, the correct positioning of dishes and other articles to be washed is of prime importance, since unless the dishes are correctly positioned with regard to the other parts of the apparatus, eiicient cleaning of the dishes cannot be accomplished. The articles to be washed must be positioned so that a maximum surface area is swept in an efficient manner by the washing Huid, and the food contacting surfaces of the dishes must be oriented so as to receive the washing fluid in the most etlicient manner possible.

Another important consideration in the designing of tray structure for dishwashing apparatus of an automatic type is ease of loading and unloading, and this consideration must be balanced against the additional considera- ICC constructed that regardless of the variations in the size and shape of the dishes loaded into the trays, these dishes p will always be correctly oriented to permit washing with tion of providing trays having a maximum capacity. With regard to the consideration of ease of loading, the tray structure which is the subject matter of the present invention was designed primarily for, but should not be considered as limited to use with top-loading equipment, that is dishwashing equipment in which the dishes and other articles are loaded into the vat of the machine and removed therefrom through an opening in the upper end of the vat, which opening is conveniently closed by a hinged lid. In such equipment, it is not always possible to install the machine so that the lid may be opened completely, that is, to a position where it is completely clear of the loading opening. For example, such equipment is often installed under a kitchen wall cabinet which over hangs the dishwashing machine and permits opening of the lid of the machine only to an angle of, say, fifty degrees rather than to an eighty ve or ninety degree position which is considered as completely open position. Where the lid cannot be openedto the fully open position, the trays must be so designed that they can be removed with the lid only partly open, such removal being necessary for periodic cleansing of the vat and for the loading and unloading of dishes from the lowermost tray, where upper and lower trays are used. For maximum capacity, it is desirable to have the dishes or other articles disposed on two levels, one above the other.

Another consideration which must be kept in mind is that dishes and other articles vary so widely in size and shape that the dishwashing machine trays cannot be designed to accommodate only specified sizes and shapes, and the designer must therefore provide structure in the trays which will support a considerable variety of sizes and shapes of dishes, and which will leave considerable leeway to the user of the machine, insofar as concerns the type of dish which is loaded into the machine. Howjev.er,while such leewayV desirable, the rack must be so a maximum efficiency.

With the above desirable attributes of article supporting tray structure in mind, the present invention has for its object the provision of the above desirable features in trays for dishes and other articles.

It is also an object of the invention to provide tray structure which is economical to manufacture, easy to use, and is suiciently rugged to withstand the usage for which it is intended.

These and other objects of the invention will be more apparent from a study of the following specification when taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a plan view of the lower tray structure, the main framework of the tray being shown, but only some of the dish supporting elements being shown;

Fig. 2 is a partial sectional View taken on line 2-2 of Fig. l;

Fig. 3 is a detail sectional view taken on line 3-3 of Fig. 1;

Fig. 4 is a detail sectional View taken on line 4 4 of Fig. 1;

Fig. 5 is a top plan View of one of the upper dish supporting elements of a iirst type as shown in Fig. l;

Fig. 6 is a side elevational view of the elements shown in Fig. 5;

Fig. 7 is a top plan View of one of the upper dish supporting elements of a second type as shown in Fig. l;

Fig. 8 is a side elevational view of the element shown in Fig. 7.

Referring now to the drawings in further detail, Fig. l shows the type of tray or rack which is used as the lowermost tray in a circular dishwasher vat having a conical bottom. The particular type of dishwasher for which this rack was designed is a dishwasher having a central rotating impeller having sloping blades which, when rotated at high speed, throw a high velocity spray of water upwardly and outwardly therefrom. In order to facilitate use of the racks with such a rotary impeller, the lowermost rack is provided with an impeller guard structure which will be discussed in greater detail presently, and surrounding this guard structure is dish supporting .structure designed to hold the dishes at the correct angle for washing by the high velocity spray from the impeller (not shown).

As shown best in Figs. l and 2, the lower rack is made up of a plurality of radially extending wires 20 which extend upwardly at their innermost portions to a point somewhat higher than the highest point on the impeller, and they extend upwardly a somewhat smaller distance at their outer ends. The inner and outer ends of the radial members 20 are shown at 21 and 22. The central portion of elements 20 is straight over most of its length, except for a central portion which is bowed upwardly as shown at 23 to dene a level which is elevated above the lowermost portion of each element 20. Attached to the elements 20 are generally triangular, downwardly extending baffle elements 24 which have the proper conguration for resting on the conical bottom wall of the vat or tub in which the tray is positioned, and which thus serve to support the lower tray. The baffles 24 also prevent swirling of the fluids in the vat as they run down the bottom wall of the vat.

The framework of the lower tray also includes a plurality of circular wires, the outermost of which is shown at 25. Next inwardly from the circular wire 25 is another circular wire 26 which rests on the raised portion 23 of the radial wires 20, and next inwardly from wire 26 is another Circular wire 27 of smaller diameter which is attached to the straight portion of each element 26 near the inner end of this portion where these elements bend upwardly to forni portion 21. A plurality of smaller circular wires 2S, 29, 3i), 31, and 32 are attached to, and surround the upwardly extending portions 21 of the radial wires 20 so as to det-ine a protective cage about the impeller of the dishwasher when the lower tray is in place in the machine. Also attached to radial wire portions 21 is a corrugated deiector element 33 which forms no part of the present invention.

The protective cage for the rotary impeller is cornpleted by a criss-cross assembly of straight wires 35 and 36, two of which elements 35 are bent at one end about the circular wire 32 (see Fig. 3) to form a simple type of hinge. The other ends of these elements 35 are bent downwardly and inwardly to form a simple catch as shown in Fig. 4.

For supporting dishes in the lower tray, there are provided two main types of dish supporting elements. The lowermost of these elements are U-shaped wire elements shown at 37 in Figs. l and 2, from which it will be obvious that these elements are supported by and attached to circular wires 26 and 27, the outer ends of elements 37 being elevated above their inner ends because of the elevation of circular wire 25. These lower elements 37 are located at equal angles with respect to radii passing through corresponding points in each element 37. The position of elements 37 can also be described by referring to them as being disposed tangentially with regard to a common circle which is concentric with the rings 25, 26, etc., the imaginary points of contact of the successive elements 3'7 with the imaginary circle being spaced equally about the circle. The function of the lower elements 37 is to serve in cooperation with the circular frame wires 25, 26, and 27, to support the lower edges of dishes positioned in the tray.

The lower tray shown in Fig. 1 also includes upper dish supporting elements, these elements being of two types as shown at 40 and 41, respectively. One of the elements 4@ is shown in Figs. 5 and 6, while one of the elements 41 is shown in Figs. 7 and 8.

The elements 4t) and 41 both have a main portion which extends the principal part of the length, and inwardly bent portions 40a and 41a, respectively, which inwardly bent portions are disposed at an obtuse angle with regard to the main body of each element. The inner ends 46a and 41a of the elements 4@ and 41 are positioned in contact with the ring 31 and are attached thereto at equally spaced points about the ring, while the outer ends of the elements 4i) and 41 rest on ring 25 and are attached thereto at equally spaced points about this ring. lt should be noted that the elements 40 are always positioned in pairs, each pair being separated from the next pair by one of the elements 41.

Elements 4d and 41 both have a central portion which is bulged outwardly as shown at 42, and the elements 46 and 41 ditfer principally in the configuration of their outer end portions.

Referring first to elements 41% as shown in Fig. 6 particularly7 it will be seen that the outer end portion of each element 4) is bent downwardly approximately at right angles to the main body of this element, and at the extreme end of the element, it is bent outwardly at right angles to the downwardly extending portion. The downwardly extending portion is shown at 4% and the end, outwardly extending portion is shown at 40e in Fig. 6.

Referring now to Figs. 7 and 8, the elements 41 are shaped quite similarly to the elements 46, except that they extend a greater distance from the center of the tray before bending downwardly to form downwardly extending portions 41k. At the lower end of downwardly extending portion 4111, the elements 41 are curved upwardly at 41C, and they have an outwardly directed portion 41d 'which rests on and is attached to outer ring 25. The

l 4 angle between the main body of each element 41 and the downwardly extending portion 41h is in the neighborhood of degrees.

It will be noted that in the assembled position of elements 40 and 41 the main body of each of these elements extends at an angle of between 10 and 15 degrees with relation to horizontal, the main body of each of these elements being sloped upwardly as it extends outwardly. It can be seen that the principal part of each of the elements 4t? and 41 is disposed tangentially to a common circle which is concentric with the rings 25, Z6, etc., this cornrnon circle having a radius greater than the radius of the common circle referred to with respect to elements 37. The downwardly extending portions 4Gb are positioned at an angle of about l() to 15 degrees with regard to the vertical, the lower ends of these portions being further from the center of the tray than the upper ends. Finally, the portions 41e extend outwardly and upwardly at an angle of about 10-15 degrees to horizontal.

The main body of each element 41 is disposed similarly to the main body of each element 46, but because of the angle between the main body of the elements 41 and the downwardly extending portions 411;, these portions 41b extend inwardly toward the axis of the tray, and are thus oriented in an opposite manner to the portions 4Gb.

A comparison of elements 44) and 41 will also reveal that the portions 41b are longer than portions 4Gb, and the result is that the curved portions 41C extend to a lower level than the lowermost point on elements 40. The curved and downwardly extending portions 41e thus form convenient rests for the lower edge of dishes placed around the periphery of the rack with the elements 40 which are on each side of each element 41 defining a limit for the peripheral movement of plates thus positioned.

The positioning of the elements 40 in pairs makes it more convenient to place elongated platters in the peripheral locations instead of plates of a round nature. The round plates would have a smaller diameter and would therefore tit into the spaces defined by each element 41 and its adjacent elements 4@ with the plate being faced inwardly and with the lower edge of the plate resting on the curve 41C of the element 41. Since elongated platters would have a longer dimension than could be accommfdated by the rack if substituted for plates in the position just described, the accommodation of the long platters bcing limited by the radius of curvature of the tub or vat, these long plates can be placed with their lower edge on two of the adjacent elements 40 and because of the fact that the junction of the main body of each element and its portion 4Gb is located nearer to the center of the tray than is corresponding junction of the elements 41, the elongated platter will be permitted to rest nearer to the center of the tray where the chord across the curved wall of the vat will be longer, and the wall of the vat will not interfere with positioning of the elongated platter.

In connection with the positioning of elements 40 and 41, it will be noted that at the end of each of the radial elements 20 and attached to the outer periphery of ring 25, is a tubular socket 45 which is disposed vertically so as to receive one of the lower ends of the inverted U shaped upper tray supporting elements 46 which are shown in Fig. 1. There are six of these socket elements 45 and three of the supporting elements 46, the elements 46 being positioned as chords of the circular ring 25. The sockets 45 and the downwardly extending portions of supporting elements 46 which are carried thereby, and the dish supporting elements 40 and 41 are so positioned with regard to each other that each element 41 terminates at a point generally intermediate two of the sockets 45, while each pair of elements 40 are attached to ring 45 at positions on either side of one of the sockets 45. With a round plate resting on one of the curved portions 41e between two elements 40 on either side thereof and in a position so that its upper surface faces inwardly, it is desired that there be no tray structure at the position of the center of the plate, and the arrangement just described leaves the maximum radial distance free for the positioning of a plate in this manner. If the elements 41 were positioned so as to terminate in proximity to the sockets 45, the downwardly extending portions of elements 46 would limit the radial distance available for positioning of plates in the manner just described.

The positioning of upper dish supporting elements and 41 with regard to the lower dish supporting elements 37 provides an important feature of the invention, for by the particular mode of disposing these elements the applicant has been able to provide two supporting positions for dishes so as to accommodate dishes of varying size and shape between adjacent upper elements 40, 40, or between adjacent upper elements 40, 41. From Fig. l, the manner in which this is accomplished will be quite apparent. Each element 40 or 41 is paired with one of the lower elements 37, the elements of each pair being staggered, in that the upper element of each pair is located a short distance about the circle from the lower element of the pair. For example, the first element 41, reading from the right hand side of Fig. 1, has a lower element 37 with which it is paired, and this is the first of lower elements 37 which will be found on Fig. 1, reading from the right side. The second upper element is one of the elements 40, and it is paired with the second element 37 shown in the drawing, reading from the right. The upper and lower elements forming a pair are generally parallel with each other, this relative disposition permitting a plate, positioned between two of the upper elements, for example the first element 41 reading from the right in Fig. 1, and the adjacent element 40, to have two possible positions, one of which will be with its lower edge against the edge of the lirst element 37 (the element which forms a pair with rst element 41), or the lower edge of the dish can rest in the space 51 which is defined by the two arms of element 37. The dish which is positioned between the two elements 40 which are shown in Fig. 1 has two available positions with regard to the lower element 37 shown paired with the first element 40 reading from the right side of Fig. 1.

It will be seen that the two possible positions for the supporting of plates will provide a substantially vertical position and another position which is more sloping, and it will be seen that dishes which are of too great a diameter to rest in the more sloping position can be mounted in the more upright of the two positions.

The provision of the bends 40a and 41a at the inner ends of the elements 40 and 41 permits the tray to accommodate dishes of varied shapes, since a dish having a rather deep upturned lip around its edge would readily t into the space between two of the upper elements 40, 41, or 40, 40, by positioning the lip in the inwardly directed space between two of the adjacent upper element portions 40a, 40a, or 40a, 41a.

The central loops or bulges 42 in elements 40 and 41 prevent the dishes from coming together and thus assist in the proper positioning of the dishes.

It is to be understood that I have disclosed herein only a preferred embodiment of the invention, and that I am fully aware that numerous variations of the trays described and shown may be made without departing from the inventive concept. The invention is therefore not to be considered as limited to the exact embodiment described and shown, but is intended to cover any practice ot' the inventive concept described herein and set forth in the appended claims.

I claim:

1. A circular, article supporting tray for use in the vat of a liquid treating apparatus, comprising spaced, conJ centric circular outer and inner frame wires, spaced, radially disposed frame wires attached to said outer and inner wires, a plurality of lower, article supporting wire elements attached to said frame in spaced positions with the center lines of successive ones of said lower elements each being tangential to one of a plurality of equally spaced points on a iirst circle concentric with said inner1 and outer frame wires, and a plurality of upper, article supporting wire elements attached to the frame and extending the full width thereof, at least the principal part of each of which upper elements is tangential to a second concentric circle of greater radius than said irst circle, each of said upper article supporting elements being paired with an adjacent lower element and being substantially parallel therewith, the upper elements being in staggered relation with respect to the lower elements.

2. A tray as set forth in claim 1, said upper elements being of two types, a rst type having a downwardly extending outer portion the upper end of which is located inA side the vertical projection of a circle concentric with the tray and passing through the lower end of said portion, and a second type having a downwardly extending outer portion the upper end of which is located outside the vertical projection of a circle concentric with said tray and drawn through the lower end of said portions of the second type upper elements.

3. A tray as set forth in claim 2 in which said upper elements of said second type terminate at their outer ends in portions extending outwardly of said outer frame wire, the lowermost point of said end portions being positioned below the level of said outer frame wire, the upper elements of said second type extending to a considerably lower level than the upper elements of said rst type.

4. A tray as set forth in claim 3, in which the upper elements of said first type are positioned in pairs, each pair being separated from the next pair by an upper element of said second type.

5. A tray as set forth in claim 1 in which said radial frame wires have a hump in their central portion, one of said circular frame wires being attached to said hump and another of said circular frame wires being located inwardly of said hump and at a lower level, said two last mentioned circular frame wires serving to support said lower wire elements.

6. A tray as set forth in claim 1 in which said lower elements are U-shaped, thus providing two positions for supporting dishes.

References Cited in the file of this patent UNITED STATES PATENTS 233,340 Fithian Oct. 19, 1880 626,128 Price Mar. 27, 1900 1,426,931 Walker Aug. 22, 1922 1,595,421 Rose Aug. 10, 1926 1,692,794 Ash Nov. 20, 1928 1,777,058 Walker Sept. 30 1930 1,971,587 Stoddard et al Aug. 28, 1934 2,001,328 Kehoe May 14, 1935 2,032,156 Stoddard Feb. 25, 1936 2,035,625 Walker Mar. 31, 1936 2,213,918 Lofstrand Sept. 3, 1940 2,216,147 Ward Oct. l, 1940 2,469,966 Idle May 10, 1949 

